1. Field of the Art
The present invention relates generally to an apparatus capable of positioning circuit substrates of different sizes of printed-wiring boards, and more particularly to such a positioning apparatus having a pair of positioning members for positioning the substrates, wherein a distance between the positioning members can be efficiently and accurately changed to suit the specific size of the substrate that is to be positioned.
2. Related Art Statement
In the art of drilling holes in a circuit substrate of a printed-wiring board, or performing other operations on the substrate, or placing various electronic circuit components on the substrate, it is a general practice to place the circuit substrate on an NC table (numerically-controlled table) which is movable along X and Y axes perpendicular to each other. Since the substrate must be positioned on the NC table with high precision, the NC table is usually equipped with a substrate positioning device for accurate positioning of the substrate on the table.
An example of a substrate positioning device of the type indicated above comprises a mounting or support member disposed on the NC table and movable along X and Y axes perpendicular to each other, a pair of Y-axis positioning members which are disposed parallel to the X axis and at least one of which is movable toward and away from the other along the Y axis so as to be engageable with opposite parallel sides of the substrate parallel to the X axis to thereby position the substrate in the Y-axis direction, and an X-axis positioning member which is engageable with the substrate to position the substrate in the Y-axis direction. This type of positioning device is therefore capable of positioning different sizes of the circuit substrates.
In the substrate positioning device indicated above, the distance between the Y-axis positioning members is changed depending upon the sizes of the substrates by the operator, by moving the positioning members toward or away from each other in the Y-axis direction, directly by hand, or by manipulating suitable mechanical means such as a screw-and-nut feed arrangement.